To build your own RotorControl device, you need the following components:

• ESP32 development board with 4MB flash memory (WROOM 32, NodeMCU, DevKitC V4). [↗]
• ADS1115 16 bit ADC module. [↗]
• 2/3 voltage divider to scale down 0-4.5 V to 0-3 V, e.g.
  $V_{\mathrm{in}} \leftrightarrow 1\mathrm{k}\Omega \leftrightarrow V_{\mathrm{out}} \leftrightarrow 2\mathrm{k}\Omega \leftrightarrow \mathrm{GND} $
• One LED with a corresponding resistor.
• One push button.
• 6-pin MINI-Din cable and a corresponding plug or socket. [↗]
• SSD1306 OLED display (optional), 0.96" with 128x64 pixels. [↗]

The links are only suggestions; various suppliers offer these parts.

Pin Configuration

The project uses the following pin configuration. Some of these pins can be changed in include/globals.h. | Hardware Pin | ESP Pin | Description / Function | | ------------ | ------- | ----------- | | LED $+$ | ESP Pin 19 | Status LED | | Push Button | ESP Pin 32 & GND |Used to reset WiFi & toggle display. | | ADS1115 SCL | ESP Pin 22 | ADC I²C Serial Clock | | ADS1115 SDA | ESP Pin 21 | ADC I²C Serial Data | | ADS1115 A0/C0 | Voltage divider $V_\mathrm{out}$ | ADC input, must not exceed 3.3 V | | SSD1306 SCL | ESP Pin 22 | Display I²C Serial Clock | | SSD1306 SDA | ESP Pin 21 | Display I²C Serial Data | | Ext. control Mini-DIN Pin 1 | ESP Pin 25 | Rotate CW | | Ext. control Mini-DIN Pin 2 | ESP Pin 33 | Rotate CCW | | Ext. control Mini-DIN Pin 3 | ESP Pin 26 (DAC) | Speed control:<br>Control unit accepts 0 to 5V.<br>ESP DAC delivers 0 to 3.3 V. | | Ext. control Mini-DIN Pin 4 | Voltage divider $V_\mathrm{in}$ | Positional voltage:<br> Control unit outputs 0 to 4.5 V. | | Ext. control Mini-DIN Pin 5 | GND | Ground | | Ext. control Mini-DIN Pin 6 | N/C | - |

[!CAUTION] Directly connecting Mini-DIN Pin 4 from the control unit's external control socket to any GPIO pin on the ESP32 or to an ADS1115 channel without a voltage divider will cause damage to these components!

[!NOTE] The control unit requires a control voltage from 0-5 V to adjust the rotor's speed. In this setup, we use the integrated DAC of the ESP32 to generate the control-voltage. However, since the DAC is limited to 3.3V, the maximum achievable speed with RotorControl is limited to approximately 60% of full speed.